A semi-automatic transmission (also known as clutchless manual transmission, automated manual transmission, flappy-paddle gearbox, or paddle shift gearbox) is a system which uses electronic sensors, processors and actuators to execute gear shifts on the command of the driver. This removes the need for a clutch pedal which the driver otherwise needs to depress before making a gear change, since the clutch itself is actuated by electronic equipment which can synchronise the timing and torque required to make gear shifts quick and smooth.
The two most common semi-automatic transmissions are-
1. Dual-clutch Transmission
2. Sequential Transmission